import { createContext, ReactNode, useContext } from "react";
import {
  useQuery,
  useMutation,
  UseMutationResult,
} from "@tanstack/react-query";
import { UserUncheckedCreateInputObjectSchema } from "@repo/db/usedSchemas";
import { z } from "zod";
import { getQueryFn, apiRequest, queryClient } from "../lib/queryClient";
import { useToast } from "@/hooks/use-toast";

type SelectUser = z.infer<typeof UserUncheckedCreateInputObjectSchema>;

const insertUserSchema = (
  UserUncheckedCreateInputObjectSchema as unknown as z.ZodObject<{
    username: z.ZodString;
    password: z.ZodString;
  }>
).pick({
  username: true,
  password: true,
});

type InsertUser = z.infer<typeof insertUserSchema>;

type AuthContextType = {
  user: SelectUser | null;
  isLoading: boolean;
  error: Error | null;
  loginMutation: UseMutationResult<SelectUser, Error, LoginData>;
  logoutMutation: UseMutationResult<void, Error, void>;
  registerMutation: UseMutationResult<SelectUser, Error, InsertUser>;
};

// type LoginData = Pick<InsertUser, "username" | "password">;
type LoginData = {
  username: InsertUser["username"];
  password: InsertUser["password"];
};

export const AuthContext = createContext<AuthContextType | null>(null);

export function AuthProvider({ children }: { children: ReactNode }) {
  const { toast } = useToast();
  const {
    data: user,
    error,
    isLoading,
  } = useQuery<SelectUser | undefined, Error>({
    queryKey: ["/api/users/"],
    queryFn: getQueryFn({ on401: "returnNull" }),
  });

  const loginMutation = useMutation({
    mutationFn: async (credentials: LoginData) => {
      const res = await apiRequest("POST", "/api/auth/login", credentials);

      const contentType = res.headers.get("content-type") || "";
      const isJson = contentType.includes("application/json");
      const data = isJson ? await res.json() : {};

      if (!res.ok) {
        throw new Error(data?.error || "Login failed. Please try again.");
      }
      if (!data?.token || !data?.user) {
        throw new Error("Invalid response from server");
      }

      localStorage.setItem("token", data.token);
      return data.user;
    },
    onSuccess: (user: SelectUser) => {
      queryClient.setQueryData(["/api/users/"], user);
    },
    onError: (error: Error) => {
      console.error("Login error:", error);
      toast({
        title: "Login failed",
        description: error.message,
        variant: "destructive",
      });
    },
  });

  const registerMutation = useMutation({
    mutationFn: async (credentials: InsertUser) => {
      const res = await apiRequest("POST", "/api/auth/register", credentials);

      const contentType = res.headers.get("content-type") || "";
      const isJson = contentType.includes("application/json");
      const data = isJson ? await res.json() : {};

      if (!res.ok) {
        throw new Error(data?.error || "Registration failed.");
      }

      if (!data?.token || !data?.user) {
        throw new Error("Invalid response from server");
      }

      localStorage.setItem("token", data.token);
      return data.user;
    },
    onSuccess: (user: SelectUser) => {
      queryClient.setQueryData(["/api/users/"], user);
    },
    onError: (error: Error) => {
      console.error("Registration error:", error);
      toast({
        title: "Registration failed",
        description: error.message,
        variant: "destructive",
      });
    },
  });

  const logoutMutation = useMutation({
    mutationFn: async () => {
      localStorage.removeItem("token");
      await apiRequest("POST", "/api/auth/logout");
    },
    onSuccess: () => {
      queryClient.setQueryData(["/api/users/"], null);
    },
    onError: (error: Error) => {
      toast({
        title: "Logout failed",
        description: error.message,
        variant: "destructive",
      });
    },
  });

  return (
    <AuthContext.Provider
      value={{
        user: user ?? null,
        isLoading,
        error,
        loginMutation,
        logoutMutation,
        registerMutation,
      }}
    >
      {children}
    </AuthContext.Provider>
  );
}

export function useAuth() {
  const context = useContext(AuthContext);
  if (!context) {
    throw new Error("useAuth must be used within an AuthProvider");
  }
  return context;
}
